Let me begin by recommending the ''Prison Break'' episode scheduled to air on April 3. It's a flashback, showing us a lot about the background of the characters, about why Michael is so devoted to his brother, and about the way that several characters ended up in prison. And, if that prison break ever actually happens, the April 3 show gives us some insight into what the convicts might do once they get out.

That said, there are two episodes before then, including one airing tonight, and there's a lot more plot-stretching in them than a viewer should reasonably allow.

I know, ''reasonably'' is not a word that should easily apply to show about a guy who breaks into prison to free his wrongly convicted brother from death row, where secrets lie in elaborate tattoos, where all sorts of schemes and plots swirl around and where the convicts seem capable of just about anything in prison EXCEPT escaping. (While looking at the new episodes, I was more than once reminded how much ''Prison Break'' is in the tradition of ''Hogan's Heroes.'' Only Hogan's gang wasn't trying to escape.)

In fact, Fox has built a belief-suspending block on Monday nights, since ''Prison Break'' is being paired with ''24,'' another show I have trouble staying with, because its plots are so outrageously, uh, outrageous.

''Prison Break,'' though, has run into a problem by being so successful. When the current TV season began, ''Prison Break'' was looking at a half-season run, building its melodrama in the fall before ''24'' came back on the schedule in January. But when ''Prison Break'' gained a following, Fox wanted more episodes, so now the show has to keep its basic narrative going, just not too far or too fast.

Which means that, tonight and next week, the show is going to stretch. And stretch. And throw in a plot turn that will make viewers wonder if they have everything figured out. (That's a sad trick straight out of ''The X-FIles.'') It's not alone in doing that, of course; ''The West Wing'' on Sunday night rather desperately tried to keep some suspense in its presidential-campaign story with a new turn of events. But in both cases, the need to keep the serialized story going works against the need to satisfy viewers.

But as frustrated as I was, I didn't hate ''Prison Break'' either. When a ''Prison Break'' DVD comes out, I'll probably eat it up, since full-season DVDs are the best way to watch ludicrous serials like this and ''24.'' At least then you can fast-forward through the dull parts, and know that you'll have some kind of resolution on the last disc.

Still, I didn't buy into ''Prison Break.'' There are some horribly slow stretches, for one thing. And, without giving away any story specifics, I am pretty sure that your patience will be tested by tonight's show and next week's.